Characterization and biological analysis of avocado seed and peel extracts for the development of new therapeutical strategies.

The avocado, Persea americana, is one of the most produced and consumed tropical fruits worldwide, so more than 1.5 million tonnes of waste are generated per year, due to by-products such as the seed or peel [1]. Their revalorisation as sources of bioactive compounds, or directly as high added-value products, would considerably reduce the negative impact on the environment and would promote the circular economy, taking advantage of their incredible phenolic richness and all the health-promoting properties associated with their presence [2]. The antioxidant and anti-inflammatory profile is the most important, beneficial for reducing oxidative stress and, thus, a lot of detrimental processes, such as neuroprotection through blocking acetylcholinesterase in neuronal synapses [3].

Therefore, in order to determine their potential, a series of in vitro tests were carried out: identification of phenolic compounds with HPLC-ESI-qTOF-MS; quantification of the phenolic content and the antioxidant capacity through methodologies based on proton/electron transfer; analysis of the ability to scavenge different reactive oxygen species (ROS); and evaluation of the inhibitory capacity on different enzymes related to oxidative stress, aging and neurodegeneration.

Results reflected two matrices rich in flavonoids (quercetin, catechin, epicatechin, etc.), phenolic acids (quinic, citric and chlorogenic acid), and procyanidins with elevated degree of polymerisation, which explain the high antioxidant and ROS scavenging activity. Specifically, avocado peel was concluded as the most phenolic-rich extract with higher antioxidant activity; however, both extracts exerted beneficial effects inhibiting some of the enzymes tested. Avocado seed and peel are pointed out as suitable options for the development of new medical, cosmetical and food strategies.

[1] Ayala, T. et al. (2014). Springer.
[2] Jyoti, D. et al. (2019). Antiox.
[3] Ameer, K. et al. (2016). Adv. Neurobiol.